1. Field of the Invention
The device of this invention resides in the area of shields that are positioned between a machine operator and the operative parts of a machine and more particularly relates to a machine safety guard and system using a plurality of such machine safety guards, each of which can be positioned, and selectively opened or closed, in front of operative parts of a machine.
2. Description of the Prior Art
Industrial machinery can cause injuries to operators thereof if they are caught within the operative parts of the machinery or struck by elements emanating from such machinery. To reduce the chances of such injuries, the government through OSHA has instituted regulations which call for protective safety guards to cover certain operative parts of a machine to prevent a worker from being caught thereby or otherwise injured as the machine operates. These safety regulations provide for protective machine guards to be positioned in front of the operative parts of machinery, some utilizing machine power cut-off switches which function when such safety guards are removed from their positions in front of the operative parts of the machinery. Frequently such safety guards can be in the form of a rigid sheet of plastic or glass which is fixed in front of the operative parts of the machinery. When such protective material is removed to gain access to the operating parts of the machinery, an electrical interlocking mechanism causes power to the machine to be turned off so that the machinery cannot be inadvertently operated when the safety guard is removed. Frequently machines require set-up for different jobs and this setting up period requires the operator to adjust elements of the machine to accomplish different functions during its operation such as using different materials or sizes of materials and/or different workpieces. It is often difficult and time-consuming to remove safety guards to gain access to the machine to change its set-up or otherwise adjust or repair such machinery, and such time-consuming procedures increase manufacturing costs.
Also well known in the prior art are light beam detectors which can sense when a light beam is interrupted for the purpose of shutting down the machinery. Such a system senses when one tries to reach towards a machine but is ineffective against projectiles flying away from the machinery which could injure a bystander.